1. Technical Field
The inventive concept relates to a variable resistance memory device, and, more particularly, to a 3-dimensional (3D) stack type variable resistance memory device,
2. Related Art
With the rapid development of mobile and digital information communication and consumer-electronic industry, studies on existing electronic charge controlled devices are expected to encounter a limitation. Thus, new functional memory devices of the new concept other than the existing electronic charge devices need to be developed. In particular, next-generation memory devices with large capacity, ultra-high speed, and ultra-low power need to be developed.
Currently, resistive memory devices using a resistance element as a memory medium have been suggested as the next-generation memory devices. Typical resistive memory devices include phase-change random access memories (PCRAMs), resistance RAMs (ReRAMs), and magentoresistive RAMs (MRAMs),
The resistive memory devices may be basically configured of a switching element and a resistance element. Also, the resistive memory devices may store data “0” or “1” according to a state of the resistance element.
Even in the resistive memory devices, the first priority is to improve an integration density and to integrate as many memory cells in a narrow area as possible. Further, in the resistive memory devices, when the plurality of memory cells is integrated in a limited area, switching performance has to be ensured.